This reminds me of something I read once in a book about false memories. 90% of psychotherapy is based on the idea that examining and talking about your experiences is helpful, but that's really just an assumption. There are some situations where it is predictably and categorically false. There are many others where it might be true but remains unproven. Debating is kind of the same way. We believe that at least some forms of vigorous debate will lead to "best of both" understanding or solutions, but can any of us prove that?